In recent years, there is a quickly increasing demand of flat-panel display devices represented by the liquid crystal display devices because of its advantageous features of thinness, lightness and low energy consumption. Especially, the active-matrix display device, in which ON pixels and OFF pixels are electrically separated and pixel switches having the function to make a video signal retained in ON pixels are provided in the pixels, is used for various displays including the portable information device.
As such a flat-panel type active-matrix display device, an organic electroluminescent (EL) display device which employs a luminescent element, has attracted attention, and research and development thereof are carried out intensively. Since the organic electroluminescent display device does not require a backlight but has a high-speed responsibility, it is suitable for moving image reproduction. Further, the luminance is not lowered at low temperature, and therefore it has the feature of being suitable also for use in a cold atmosphere.
Generally, the organic electroluminescent display device comprises pixels arranged in rows and columns. Each pixel comprises an organic electroluminescent element, which is a luminescent element, and a pixel circuit configured to supply a drive current to the organic electroluminescent element. Display operation is performed by controlling the luminance of the organic electroluminescent element.
Moreover, in an organic electroluminescent display device, various kinds of corrections are carried out on video signals in order to reproduce high-quality images. Here, for example, a technique of detecting the drive state of an organic electroluminescent display device to carry out various kinds of corrections has been disclosed.